ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: poohead on August 22, 2010, 10:19:56 am

Title: Sounds
Post by: poohead on August 22, 2010, 10:19:56 am: How does two musical instruments sound differently when they are playing the same note?
Title: Re: Sounds
Post by: /0 on August 22, 2010, 03:14:28 pm: Different musical instruments allow for different overtones (higher harmonics) when a note is played. The types of overtones that an instrument allows gives it its unique sound.
Title: Re: Sounds
Post by: cypriottiger on August 22, 2010, 04:24:39 pm: i did the same question an hour ago :) the one with the double bass and violin?
they may play the same note but i guess the questin really just requires logic and the general knowledge that a double bass produces a deep sound (lower frequency) than the violin that produces a higher pitch (high frequency)
Title: Re: Sounds
Post by: /0 on August 22, 2010, 04:49:03 pm: I think what op meant was for example if a piano and a violin play notes of 512Hz, why do they sound different?

Take a guitar, for example. The resonant frequencies are: $f = \frac{nv}{2L}$ . If you play the fundamental, $f_1 = \frac{v}{2L}$ , then you can simultaneously excite higher harmonics, such as n=2,3,4... etc. In fact, if you play any frequency, you will excite overtones of that frequency.

The degree to which these overtones are excited depends on the type of instrument, and in a sense defines the sound of the instrument. I remember seeing in year 12 that violins tended to excite much higher overtones than a piano, which is why they sounded more shrill. In fact, some of the higher overtones can sound rather bad, so in the really top-class instruments they use methods to cancel them out, such as pinching the string at a certain point to cancel out the standing wave of that particular harmonic, thus improving the sound quality of the instrument.
Title: Re: Sounds
Post by: pooshwaltzer on August 22, 2010, 05:17:27 pm: I, alone, could play just as well as the entire London Symphony Orchestra...on the moon.
Title: Re: Sounds
Post by: poohead on August 22, 2010, 06:12:33 pm: wow u guys seem to know a fair bit
thanks :D (Y)
Im struggling with sound :(
so another sound question:
how does resonace & standing waves in a column of air relate to Kundt's Tube